On Thu, Feb 10, 2011 at 1:23 AM, Phillip Susi <psusi@xxxxxxxxxx> wrote: > On 02/09/2011 04:39 PM, Alan Cox wrote: >> >> The old IDE driver defaulted to unlocking based upon years of experience >> in the real world. Jeff insisted on being different, and surprise >> surprise everyone ended up setting distro defaults that were different. > > What experience? The only reason that I have heard for unlocking it is to > maintain compatibility with the old ide driver which did so. What reason > does Linux have to access an area of the disk that the system has made clear > it should not? Aside from the upgrade case, I can not see any upside to > this, only the downside of breaking on systems that work fine on Windows, > because it does not disregard the platform request to leave that part of the > disk alone. I wish it was so simple.. HPA was originally used for accessing disk area > 128GB (so default to unlock) on systems with buggy BIOSes and then on some laptops vendors started to use it in _theirs_ Windows versions for recovery area (so default to lock!), somewhere in between fakeraid vendors came in to the game and finally we had conflicting Linux defaults more as a result of premature deployment by some distributions than a policy decision (since there were no feature implemented to make a policy decision for).. oh and please do not forget about distribution upgrades/downgrades -- not a common case in Linux world but such things really do happen.. Do you see a problem now? You just cannot make a one policy nowadays and whatever policy you decide on you're going to break some setups.. :-) HPA policy is system _and_ disk _and_ specific configuration dependent so there is no way for kernel alone to get all different cases right. The best we can do is export all data points to user-space and let it & user deal with the resulting mess.. Thanks, Bartlomiej -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
